3.2 Prefixes for Location

The endocrine system is made up of a series of glands that regulate hormones throughout the body; all the endocrine glands are shown in Fig. 3.3. It is important to differentiate between endocrine glands and exocrine glands (Fig. 3.4). Endocrine glands secrete hormones within the body and the blood, whereas exocrine glands secrete chemicals outside the body (Betts et al., 2013). Their names suggest their function in that endo- means “within” and exo- means “out” (Betts et al., 2013).

An ectopic pregnancy is a pregnancy outside its normal location. Fig. 3.5 shows the normal location of a pregnancy within the uterus and an ectopic pregnancy in an ovary, cervix, fallopian tubes, or abdomen. An ectopic pregnancy can be life threatening because the developing embryo has no room to grow. This condition can result in the surrounding area rupturing and causing the individual to hemorrhage internally (Betts et al., 2013).

As can be seen from Table 3.3, there are a number of prefixes with similar meanings. They are, however, used very differently in medical terminology. With practice and familiarity, it will become easier to know which prefix to use for a particular term.

An epidural (Fig. 3.6) involves some form of injection into a patient’s spine to stop feeling to the area of the body below that point in the spinal cord. Epidurals are performed on patients in labour or for surgery to the lower extremities (NHS, 2020). A similar procedure is called a lumbar puncture or spinal tap, which involves taking a sample spinal fluid for analysis.

Intradermal injections are commonly used for tuberculosis testing, analgesics, anesthetics, and allergy testing. An intradermal injection is placed just below the skin surface, as seen in Fig. 3.7. Another use of the prefix intra- (“within”) is seen in the medical term intrauterine device (Fig. 3.8), which is a means of birth control that is placed within the uterus.

The parathyroid glands are located “along the side of” (para-) the thyroid gland. There are four of them, two on each side of the thyroid, and they are a part of the endocrine system. Fig 3.9 shows the location of the parathyroid glands (in pink) with the thyroid gland beneath.

The pericardium “surrounds” (peri-) the heart, and it both holds the heart in place and protects it (Medline Plus, 2022a). In Fig. 3.10, you can see that the pericardium provides cushioning for the heart, similar to the manner that the balloon in the figure is cushioning the fist.

There are various types of medical prostheses, and the term prosthesis comes from the suffix -thesis (“put” or “place”) and the prefix pros- (“before” or “forward”); it literally means “to place before,” as in replacement. Prostheses, or prosthetic implants, can be used to replace a missing body part or function and are intended to restore normal function. A cochlear implant (Fig. 3.11) is an example of a medical prosthesis and is used to treat sensorineural deafness (Yawn et al., 2015).

The two prefixes in Table 3.8 have the same meaning but are used differently depending on the medical term. The prefix re- (“back” or “behind”) can be found in terms such as relapse and remission. Relapse has the suffix -lapse (“to slide”), which makes the literal meaning “to slide back.” Patients experience a relapse when their symptoms come back, which is the opposite of a remission. Remission has the suffix -mission (“to send”), which makes the literal meaning “to send back.” When a patient is in remission, their symptoms and pathology lessen or go away.

The term retroperitoneal literally means “pertaining to” (-al) “behind” (retro-) “the peritoneum” (peritone/o). The retroperitoneal space contains the kidneys, adrenal glands, pancreas, nerve roots, lymph nodes, abdominal aorta, and inferior vena cava (Medline Plus, 2022b). Fig. 3.12 is an image of the retroperitoneal space and the organs present within it.

Figure 3.13 above was introduced earlier in the book and shows four different types of brain hematomas and hemorrhages. Now that you have a better understanding of prefixes, it is possible to interpret the different types shown in the diagram:

• An epidural hematoma is a mass of blood “above” (epi-) the dura mater.
• A subdural hematoma is a mass of blood “below” (sub-) the dura mater.
• A subarachnoid hemorrhage is excessive bleeding “below” (sub-) the arachnoid, which is a thin layer of tissue on the dura mater (Cleveland Clinic, 2022).
• The final type of hemorrhage in this figure is the intracerebral hemorrhage, which literally means “pertaining to” (-al) “withi”n (intra-) “the cerebrum” (cerebr/o).

A transdermal patch is an effective route for giving medication to a patient. The medication is absorbed “through” (trans-) the skin.  Nicotine patches are a common example of this medication route. Other common uses for transdermal patches include birth control, nitroglycerin for angina, and analgesics for pain. Fig. 3.14 shows an example of a transdermal patch being applied to a patient.

Transurethral resection of the prostate (TURP) is a procedure often used to treat benign prostatic hyperplasia (BPH) (Johns Hopkins, 2022). Fig. 3.15 shows the procedure being completed using an instrument that is placed “through” (trans-) the urethra to remove some of the enlarged prostate.